Automatic fuse cut-out



Jan. 18 1927.

I J. w. NOLAN AUTOMATIC FUSE CUT -'OUT 2 Sheets-Sheet 1 Original Filed Nov. 12, 1917 Jan. 18,1927.

J. W. NOLAN AUTOMATIC FUSE CUT-OUT 2 Sheets-Sme t 2 Original Filed Nov. 12, 1917 IE; y

I EJMWMQ? 306W @(QOXCLW I I Patented Jan. 18, 1927.

UMTED STATES JOHN WILLIAM NOLAN, OF PAVITUCKET, THORNLEY, F PROVIDENCE, RHODE REIODE ISLAND. ASSIGNOR TO VIILLIAM H. ISLAND; ELLEN S. THORNLEY EXECUTRIX OF SAID WILLIAM H. THORNLEY, DECEASED.

AUTOMATIC FUSE CUT-OUT.

Application filed November 12, 1917. Serial No. 201,547. Renewed October 26, 1921. Serial No. 510,534.

This invention relates generally to electrical appliances, and more particularly to fuse cutouts used in connection with threephase electrical circuits, or to four wire twophase circuits, etc.

The primary object of the invention is to provide a mechanically operated means whereby when a fuse in any one of the circuits is blown, the switch in another circuit will be automatically opened so that all of the power circuits are open. In three-phase circuits, now commonly used, one of the fuses may be blown, but this does not entirely break the circuit since it will continue to operate on a one-phase circuit tending to overheat the motor, with a consequence of overheating, overloading and unhalancing of the entire circuit, and difficulties well known to those skilled in the art will be experienced By means of this invention however, im-

mediately upon any one of the fuses being blown, the switch of an adjoining phase of the same circuit will be opened, thus altogether stopping flow of current to the mo tor.

The above mentioned object of the inven tion is attained by the combination and arrangement of parts and the details of construction as will be hereinafter fully de- 34) scribed and claimed.

In the accompanying drawings forming part of the application and wherein;

Fig. 1 is a diagrammatic representation of a three-phase electric circuit employing devices constructed in accordance with this invention therein;

Fig. 2 is a side elevation of one of the devices or combined switches and fuses;

Fig. 3 is a sectional view taken on the 4i? plane indicated by the line 3--3 of Fig. 2;

Fig. 4; is a central vertical sectional view of the switch, and fuse;

Fig. 5 is a sectional view taken on the plane indicated by the line 5-5 of Fig. l;

Fig. 6 is a front view of the fuse memher and the pins to which its ends are connected; and

Fig. 7 is :1 sectional view taken on the plane indicated by the line 77 of Fig. 4.

* In the drawings above briefly described similar reference characters are placed upon corresponding parts throughout the several views and reference is herein made to the various elements by their respective indices.

To this end numeral 1 designates a nonconducting base plate upon which is mounted a switch blade 2, the latter being pivoted at one of its ends by means of a pin 3 which extends through a pair of posts 4 secured to one side of the base plate. Secured also to the base plate 1 is a contact clip 5 which is engaged by the other end of the switch blade 2 when the switch is in closed position. Conducting wires are adapted to be connected to the post 4 and the clip 5 so that when the blade 2 is in engagement with the latter the connection between these wires will be completed. I

Secured rigidly to the base plate 1 and extending outwardly from the same is a supporting arm 6. This arm 6 is of non-conducting material, preferably fiber, and carries at its outer end a metallic head 7, the latter having a vertical aperture 8 therein through which a conductor rod 9 is extended. The rod 9 is maintained in fixed relation to the head 7 by means of set screws 10. Threaded upon the lower end of the rod 9 is a binding nut 11 bet-ween the inner end of which and the lower side of the head l is clamped one of the circuit wires. The other end of the rod 9 is flattened as at 12 and extends into the lower end of an insulating tube or casing 13 and passes through the lower insulating disks 13 and 13 which are arranged within the lower end portion of the tube 13. The upper end of the rod 9 is connected to an element or strip 1 1, and the upper end. of this strip 14 is connected to the lower end ofa second conductor rod 15 which latter is similar and complemental to the element 9 and extends through upper insulating disks 13 and 13 and through an aperture 16 which extends vertically through a metallic head 17 carried on the outer end of a movable arm or lever 18. The elements 9 and 1.5 also pass through packing'and insulating material 13 such as asbestos or the like, this packing being sufficiently loose around the element 15 to permit the latter to be slid therethrough and through the disks 13 and 13 by the upward movement of the head 17 of the lever 18. The inner end of this lever 18 is pivoted between a pair of posts or bearings 19 secured to the base plate 1. The rod 15 is held in fixed rela tion to the head 17 by means of set screws 20, and threaded upon the upper end of the IOU pin is a liiinding nut 21 between the inner end of which and the upper of the head 1? is clamped another of the circuit wires It is to be understood that the elements 9 and are conductors through which the current passes to and from the fusible eleiuent lhe lever 18 curries a depending lug; or nose which engages the switch blade 2 and holds the same in closer position against the tension of a spring- 23 which bes against the same and tends to throw the r into open posnion. T he outward movement oi the switch blade is limited by a yoke EH curried bythc base plate 1.

Normally the use strip serves as a tie .or tension member to ho d the switch restraining lever 18 in the position for holding the switch closed. Butwhen the fuse strip becomes overheateigl by eficessive current and is melted, or so much softened that it no longer has strength to hold said restraining lever. then the stress constantly exerted from the spring 23 through switch blade lug 22 and restraining lever 18 causes the fuse to part. Preferably .the fuse is provided with a portion of reduced cross sectional area in its middle in order that the parting may occur at a definitely lknown point. A: the tube 13 and insulating heads 13" are not connected to the metallic heads 7 and 17, except as they are tied thereto by the fuse strip and associated coneuctors 9 and 1.3 such casing does not prevent such displacement of the restraining lever 18 as is necessary for the result just described to take place. The casinc and the asbestos packings in the ends thereof prevent damage being caused by sparks orhot metal when the use is blown, while the quick separation of the parts of the fuse caused by .the spring driven movement or" the restrainin elever suppresses the tendency of an arc to term between the terminals of the ruptured tuse.

Heretolore great diliiculty has been ex- 1 'nced in three-phase three-wire electric (IECUliS because where one out the Fuses is blown the circuit is not entirely brol-zen since it will continue to operate on a one-phase circuit through the other two .wires. To overcome this difficulty, three of the above described devices or combined swi esand fuses are employed. and the 1 n which this done 1.. i .lustrated di annnat 1. In this view the three circuit n s I ated '26 and 27. and the switches eredesignated 28. 29 and 30, each switch being a duplicate ofthe unit inst described in detail. Each of he circuit wires is connected with one end of the iue of one switch. and the other end of said use connected by a wire, 31, 32 or 33 respectivenx. with the contact clip 5 of another switch. Thereby the circuit wire is connected with the conductor 36 leading from switch the circuit. wire 26 is connected with the conductor 3 leading troin switch 28 and the circ t wire 9' is connected with the conductor lee ing from the switch It will thus be seen that the circuit of each Off the wires and 27 passes through the fuse strip off one of the switches and then through'the switch blade of another so that in case one tuse is blown, its switch blade will be opened to open the circuit through another of the: wires his obviously breaks the circuit through two of the wires and prevents it i'ronr working on a one-phase circuit to overheat and otherwise damage the devices operated by the same.

From the foregoing. taken in connection with the ucccunpnnying drawings, the construction, use and operation of the device will be readilv understood without a more extended explanation.

As va ious changes in form. proportion and in the minor details of construction may he resorted to without. depar from the spirit of this invention. it is to be understood that I do not wish to be limited to the construction herein shown and described other than .as claimed.

I claim:

1. In eombiinition a pol qflnzse circuit harine'a niuulzer oi conducting lines, circuit controllers each consisting of a switch and a fuse. the ruse of each controller being: conjwith oneoi, the conducting lines and switch of another controller, and ch oi each controller being in the circuit of a ditl'erent line from that in which its own fuse is connected and each controller including: means tending to open its switch and restraining means connected with its fuse and eti'ective .to minim? the switch in closed position while said l'use retains its inti ii.

lne coin jiination of a plurality ol circuit controllers ezu-h includingza switch havng seg...:ruteterminals, a fuse, a spring tend- 111;.1 to open said switch, and restraining means normally held by the associated fuse in position to prevent opening of the switch. said controllers lj eingfi coupled with the l nes of :1 polgwiiliase circuit in such fashion that the :t e of each controller is arranged in seiii nrthe same line with the switch of a difierent controller.

3. ii cvfety ircuit controller eomprisingr s itch adapted to be connected with one o conductors of a polyphase circuit.

11 us tending to open said switch. a 1. st inning; device adapted to hold sta d c lit;

rangg ed to prevei'it such displacement; thereof, said tnsible condiu-tor being connected with a ditt'erent conductor of the circuit than that with which said switch is connet-tied.

at. A circuit controller for polyphase circuits comprising a switch in connection with one phase of such a circuit and being under tendency constantly to open, a restraining deuce tor such switch having a portion overlapping a part ot the switch and being so mounted that force exerted by the switch tends to displace it to a position wherein it no longer opposes opening movement of the switcn, and a 'tuse in connection with a ditt'ercnt phase ot' the circuit coupled to such rest raining device and normally preventing such displacement thereof, but adapted to release the restraining device when its integrity is destroyed by fusing.

A polyphase circuit contnoller comprising a switch electrically connected in one phase of the circuit, said switch including a pivotally mounted blade under tendency constantly to move into open position, a restraining device having a lug overlapping a part of said switch blade and being mounted to move in a path which permits displacement of said lug out of engagement with the switch blade, said lug being arranged so that the force exerted by the switch blade tends so to displace it, and a use electrically connected in a different phase (it the circuit and mechanically connected with said restraining device so as to prevent displacement: thereof while its own integrity continues:

(3. A safety controller comprising a switch connected with one conductor of a polyphase circuit: and incli'iding a pivoted switch b ade under constant tendency to be moved into open position, a pivoted restraining device having a lug overlying a part of said blade andv so arranged that the force exerted by the opening tendency of the blade tends to move said lug about the pivot of the restraining member, such movement of the lug being in a path which carries it out of the path n which the switch blade moves when opening. a tixed abutment, and a. fuse connected to said almtmenti and to said restraining device in position to hold the latter in its restraining relatioi'i to the switch. said tuse being electrically eonnectetil. in a second phase ot the circuit.

T. A sat'ety controller for POlyIJlHISO circuits coniprisii'ig a switch electrically conneeted with one oi the phases of such cireuit, a lever tulcrumed in a position to en- 1 with andv normally hold the switch closed and to be swung about its fulcrum by the opening movement of the switch, a fusible conductor in electrical connection with a second phase of the circuit being mechani- (tally coupled with said lever, means normalty ctimctiiig with said fusible conductor to hold said lever in its switch holding position, and means normally tending to open said switch against the holding tendency of said lever and tusible conductor.

8. A safety polyphase circuit controller comprising a. switch adapted to be connected with one of the conductors of: a polyphase circuit, a t'usible conducting element adapted to be connected with a second conductor of such circuit, a movable holder secured to the t'nsible conducting element and held thereby against llrOVCIIlQllt, means for open ing the switch, and means normally coacting with said nisihle conducting element and holder to hold said switch closed, but allowing the latter to be opened by the first said means when the fusible conducting element is fused.

9. The combination with a polyphase circuit of means for breaking the circuit of one phase by the breaking of a circuit of another phase comprising an independently openable circuit breaker element in the circuit respectively oi? each phase adapted to be controlled by a predetermined current in its circuit, a second circuit breaking element respectively in the circuit of each phase resiliently pressed in a direction to open the circuit of its respective phase, and each of said second circuit breaking elements being openable independently ot each other, and means whereby the opening pressure on each of said s *end circuit breaking elements is respectively transmitted to one of said first circuit breaking elements connected in a different phase.

It). The combination with a polyphase circuitot a circuit br aking element in the circuit cl each of said phases respectively and each ot. said elements being openable independently of each other, a second circuit breaking element in the circuit of each of said phases res 'iectively, and openable independently of each other. the first named ele' ments of each phase being in series respectively with the second named elements of each phase, and means for causing the opening of one of said second named element's upon the opening ot' one of said first named elements in a ditl'erent pl'iase.

ll. The con'ibination with a polyphase circuit ot a circuit tweaking element in the circuit of each of said phases respectively and openable independently ot each other, a second circuit tweaking element. in the circuit oi each of said phases respectively and openable independently of each other, each of said second circuit breaker elements being biased to move to open position, and means whereby each 01 said second circuit breaking elements is held in closed position respectively by one of said first named circuit breaking elements connected in a. terentphase of the circuit.

& 1,614,533

12. The combination with a polyphase circuitof a circuit breaking element in the circuit of each of said phases respectively and openable independently of each other upon the passage of an overload current, a

second circuit breaking element in the circuit of each of said phases respectively and openable independently of each other, each of said second circuit breaker elements bemy hand.

JOHN lVILLIAM NOLAN. 

